以離散元素法探討加勁砂土層在淺基礎受載重下之力學

台灣地狹人稠，都市土地之有效利用為工程師們的一大挑戰，因為台灣位於歐亞板塊與菲律賓板塊交界，活動斷層附近之土地利用更需了解斷層錯動對附近工程設施之影響。斷層錯動造成地表變形可能會引起過大角變量，導致斷層上方或是斷層附近的建築物損壞並導致結構物坍塌，由於此類災害不可避免，如何利用大地工程之減災措施來降低人財損失為近年來重要的研究課題。前人研究中大部分以有限元素法模擬斷層錯動之力學行為，然而利用有限元素法可能無法處理或模擬斷層錯動時造成之大變形以及裂縫產生與延伸無法有效於模型中觀察，所以本研究利用離散元素法，使用 PFC2D 軟體，模擬基礎載重下土壤承載力微觀變化與斷層錯動後斷層上部覆土之位移情形。廖泓韻(2013)研究中提到顆粒接觸勁度、剪切勁度以及顆粒基本摩擦角對整體之宏觀摩擦角有關;Sawwaf(2010)以有限元素模擬地工格網在砂土層平板加載的加勁效果，並以物理實驗比較，本研究利用廖泓韻之參數做原始建模，並於模型中鋪設地工格網進行平板加壓，再以 Sawwaf 物理試驗之結果做參數驗證，最後利用已驗證之參數進行不同摩擦角土壤承載力模擬，再以改良的模型模擬不同的層數、格網寬度及格網位置做承載力比較。

關鍵字

離散元素法；平板載重試驗；地工格網；微觀

並列摘要

Taiwan is located in between the boundaries of the Eurasian and Philippine plate, so the use of the land over the fault is a major issue. The dislocation provokes a deformation in the surface causing an angular distortion; it could make the upper side of the fault or the architectures surrounding it to get damaged, causing structures to collapse. We can decide to use bigger projects, preventing methods to reduce human and financial losses. The majority of previous studies take finite element methods to simulate the behavior of faults, and use the disadvantages of grid simulations like: particle- degree rotation and limited displacement, the inseparability of particles, the inability to detect particle contact situation, large changes can’t be simulated and the show up and extension of cracks can’t be observed. Therefore, this research uses discrete element method-PFC, simulating the dislocation of the fault after the overburden of the top of the fault is affected by the displacement situation of the bottom part’s dislocation. In the research of Liao(2013) ,the stiffness of the particle’s contact, shear stiffness and particle basic friction are related to the integral friction; the research of Sawwaf (2010) simulate Geo-grid in sand layers loading plant by FE and compare it to the physical experiments. This research do the original model by Liao's codes and add the grid in the model to do the loaded plant test, then compare to Sawwaf's laboratory model. The future research directions are for increasing the geo-grid in layer, and simulate the lower friction of angle to discuss the result of Geo-grid, and use the improved model to compare the bearing capacity.

並列關鍵字

discrete element method ； plate load test ； microscopic ； geo-grid

參考文獻

04. 宋丘言，「使用離散元素法進行乾砂直剪試驗模擬」，國立中央大學土

earthquake surface fault rupture”, Seismic Fault-induced Failures, 55-

80(2001).

02. Cundall, P.A., and Strack, O.D.L., “A discrete numerical model for granular

05. Sawwaf, M.E., “Experimental and Numerical Study of Eccentrically Loaded

國際替代計量

以離散元素法探討加勁砂土層在淺基礎受載重下之力學

未授權

主題瀏覽